Guest checkout and duplicate customers in Shopify

Guest checkout makes buying quick, and it is hard on your customer list. A shopper who buys three times as a guest, with a slightly different set of details each time, can end up as three customers in your admin. This guide explains how that happens, what it costs, how to find the duplicates without merging the wrong people, and what Shopify’s own merge will and won’t do.

What Shopify records at a guest checkout

A guest order still needs a customer. Shopify’s Help Center lists “Placing an order” among the actions that create a customer profile, along with signing up for your mailing list or an account and abandoning a checkout. The same page says: “Each profile can have only one email address.”

That makes the profile only as good as what the shopper typed. A guest doesn’t sign in, so the contact details entered at checkout are what your store has to go on. Your checkout settings decide whether shoppers give an email, or a choice of phone number or email (Checkout form options). The contact method at checkout is “Phone number or email” or “Email”.

How accounts link orders to profiles

Signing in changes what Shopify has to go on. Shopify’s Help Center says a customer with an existing profile signs in with that profile’s email, and an email that isn’t tied to a profile “creates a new profile automatically” (Customer accounts). Accounts use a one-time code sent by email, with no password.

Changing an email address doesn’t merge profiles either. The same page says merging is something you do in your admin.

How one shopper becomes several profiles

Merchants in the Shopify Community describe the same handful of patterns again and again. These are merchant reports, so treat them as common experience rather than documented platform rules.

• A second email. Customers switch between work and home addresses, or move to a new one (merchant report).
• Phone one time, email the next. A shopper checks out with a phone number once and an email the next time (merchant report).
• A wallet fills in a different email. One merchant found Apple Pay passing an email that differed from the store account (merchant report). Another saw PayPal appear to override the checkout email (merchant report).
• A typo. A mistyped email creates a separate customer, and the right address can then be “already taken” when staff try to correct it (merchant report).
• An account holder checks out as a guest. One merchant found an active account plus one or more extra profiles for the same person (merchant report).
• A forgotten password. Customers forget they have an account and make another (merchant report).

Several of these have nothing to do with guest checkout. The last one happens on stores that require accounts. For the full list of causes, with what Shopify documents and what merchants report, read why Shopify creates duplicate customers.

What split profiles cost a store

The cost shows up in small, everyday places. Merchants put it plainly: “It is a mess for looking up past orders,” and it is “extremely time consuming to understand new vs repeat customers.”

Here is one person in MergeGuard’s demo store: Amelia Hughes: 3 profiles with 4, 3 and 2 orders → one customer with 9 orders Demo store (Northsail Supply). On profiles, she looks like three ordinary customers. As a person, she is one of the store’s best.

The same split runs through everything that counts customers:

• Support. Staff search several profiles to find an order while the customer waits.
• Reporting. One loyal buyer appears as several one-time buyers, which pulls down your repeat purchase rate.
• Loyalty and VIP. Spend spread over profiles can keep a real VIP under your threshold on every one of them.
• Email. Two subscribed profiles mean the same person can get the same newsletter twice.
• Discounts. A regular can look like a new customer and receive a welcome or win-back discount meant for someone else.

Should you turn off guest checkout?

Requiring accounts adds a step for every shopper, and it doesn’t stop duplicates on its own: shoppers who forget an account create another one. Guest checkout keeps buying quick, and you clean up afterwards. We haven’t seen a primary source with numbers on what requiring accounts does to sales, so we won’t quote one.

If you do want accounts, Shopify has a setting in Settings > Checkout to “Require customers to sign in to their account before checkout”. With it on, contact is limited to email, and Shopify hides fast checkout buttons such as Apple Pay from the online-store cart, so no checkout skips the sign-in (Checkout form options).

Our view, for most stores: keep checkout easy, and put the effort into finding and merging duplicates carefully. Stores where customers must sign in for other reasons, such as wholesale pricing, may decide differently.

How to find guest checkout duplicates

Start with the details that profiles share, and rank them. Some signals are strong. Others mostly catch different people who happen to share something.

Shopify’s customer search finds one customer at a time by name, email, phone or address. That works when a customer tells you about their duplicate. For a backlog, merchants export customers to a spreadsheet and sort by phone and address (merchant report), or use an app that groups likely duplicates for review.

Keep the false matches in mind. Merchants worry most about merging two different people, because one could then see the other’s information (merchant report). A shared address alone is a reason to look closer. It isn’t proof. In MergeGuard, you can mark relatives as family members so they stay separate.

The rules of a Shopify merge

Before you merge anything, know what Shopify’s merge does. These lines are quoted from Shopify’s Help Center.

• Two at a time. “To merge more than 2 customers together, repeat the procedure for each additional profile.”
• Permanent. “After the profiles are merged, you can’t reverse the process.”
• Silent. “The customer isn’t notified when you merge their customer profiles.”
• Consent carries over. “If the customer is subscribed to email and SMS text marketing in one profile, but not in the other, then the merged profile is subscribed.”
• Orders stay attached. Orders from both profiles appear under the merged profile, and Shopify says “Orders are permanently associated with the customer account that placed them,” so you can’t move single orders between profiles.

Shopify combines orders, draft orders, addresses, email, phone, name, notes, tags, tax settings, timeline events, credit cards, customer accounts, gift cards and discounts. Combined notes can be up to 5,000 characters and combined tags up to 250. You review and select the merged profile’s details before you confirm.

Shopify also refuses some merges, for example when either profile has ever had a subscription contract or has store credit. Those rules apply to every app too. The nine cases are on why Shopify blocks some merges.

A safe order of work

1. Fix typos first. Correct mistyped emails before you merge, so the merged customer keeps the right address. One early user of Shopify’s merge reported that the typo address won (merchant report).
2. Start with the strongest evidence. Same phone plus a near-identical email is a better first batch than shared addresses.
3. Leave relatives and flatmates alone. Mark them as not duplicates and move on.
4. Check what happens to subscriptions. If any profile in the group is subscribed, the merged customer will be.
5. Watch your email flows during a big cleanup. One merchant saw old abandoned-cart flows fire after merging and paused flows while cleaning up (merchant report).
6. Keep a record. Note what you merged and why. A merge can’t be reversed, so the record is how you answer questions later.

The safe merge checklist turns these into a list you can work through.

Keeping new duplicates down

Guest checkout will keep creating some duplicates, so plan for upkeep rather than a single cleanup. A short review every week or month catches new groups while they are small. Fixing typos at the source stops one common cause. If you use an app with automatic merging, keep it to the matches you would confirm anyway, and keep close calls for review.